Sensor classification introduction

According to their use, sensors can be classified as:

Pressure Sensing and Force Sensing Sensors Position Sensors Level Sensors Energy Sensors Speed ​​Sensors Thermal Sensors Acceleration Sensors Radiation Sensors Vibration Sensors Humidity Sensors Magnetic Sensors Gas Sensors Vacuum Sensors Biosensors, etc., can divide the sensor by its output signal. for:

Analog sensors - convert non-electrical quantities that are measured into analog electrical signals.

Digital Sensors - Convert the measured non-electrical quantities into digital output signals (including direct and indirect conversions).

膺 digital sensor - the amount of signal to be measured is converted into a frequency signal or short-cycle signal output (including direct or indirect conversion).

Switch Sensor - When a measured signal reaches a certain threshold, the sensor outputs a set low or high signal accordingly.

Under the influence of external factors, all materials will make corresponding and characteristic responses. Among them, materials that are most sensitive to the outside world, that is, those that have functional properties, are used to make sensor sensitive components. Sensors can be divided into the following categories from the perspective of the applied materials:

(1) According to the type of material used, the metal polymer ceramic mixture (2) according to the physical properties of the material conductor insulation semiconductor magnetic material (3) according to the crystal structure of the material single crystal polycrystalline amorphous material and the use of new materials close The related sensor development work can be summarized in the following three directions:

(1) Explore new phenomena, effects, and reactions in known materials and then make them practical for use in sensor technology.

(2) Explore new materials and apply known phenomena, effects, and reactions to improve sensor technology.

(3) Explore new phenomena, new effects, and reactions based on the research of new materials, and implement them in sensor technology.

The progress of modern sensor manufacturing depends on the strength of the development of new materials and sensitive components for sensor technology. The basic trend of sensor development is closely related to the application of semiconductors and dielectric materials.

According to its manufacturing process, sensors can be distinguished as:

Integrated Sensor Thin Film Sensors Thick Film Sensors Ceramic Sensors Integrated sensors are manufactured using standard process technologies that produce silicon-based semiconductor integrated circuits. Parts of the circuits that are used to initially process the measured signal are also typically integrated on the same chip.

The thin film sensor is formed by a thin film of a corresponding sensitive material deposited on a dielectric substrate (substrate). When using a hybrid process, some circuits can also be fabricated on this substrate.

The thick film sensor is made by coating a ceramic substrate with a slurry of a corresponding material. The substrate is usually made of Al2O3 and then heat-treated to form a thick film.

Ceramic sensors are produced using standard ceramic processes or some variant process (sol-gel, etc.).

After an appropriate preliminary operation is completed, the formed element is sintered at a high temperature. There are many common characteristics between the two processes of thick film and ceramic sensor. In some aspects, it can be considered that the thick film process is a variation of the ceramic process.

Each process technology has its own advantages and disadvantages. Due to the low capital investment required for research, development and production, as well as the high stability of sensor parameters, it is reasonable to use ceramic and thick-film sensors.